Patrick Willisadmits it. The 49ers' inside linebacker hasn't been his playmaking self this season, though not for a lack of trying.

It's just that teams are making sure an oversized offensive lineman blocks the three-time Pro Bowler on most every play.

"I remember there were times when I could just stack and run and ... most of the times you never get touched," Willis said Wednesday. "Now, you're starting to feel it from every angle. They say, 'We have to put a hat on one of the best players at all times,' and they're doing that.

"It's been a little frustrating not having the big plays that I've wanted to have."

By no means has Willis gone in the tank since becoming the highest-paid linebacker in NFL history during the offseason. His 47 tackles lead the 49ers and are tied for 15th-most in the league.

Nice, but Willis has led the league in tackles twice in three years. With pulling guards in his face this season, someone else needs to collect those tackles until Willis figures out a way around the mismatch blocks.

"The rest of the season, whatever happens - big play or no play - I just want to do everything I can to help my teammates win," Willis said. "When the plays come, I'll make them."

He's back: Panthers receiver Steve Smithpracticed Wednesday, three weeks after sustaining a high ankle sprain, and is expected to play Sunday against the visiting 49ers.

He'll catch passes from quarterback Matt Moore, who got his starting job back this week after three weeks on the bench.

Briefly: The 49ers re-signed fullback Jehuu Caulcrick, who they released twice in two days last week, back to the practice squad. ... Center Eric Heitmannis doubtful with a neck injury. ... Tight end Vernon Davisis day-to-day after an MRI exam revealed a knee contusion after Sunday's game.